How to Keep the Bit Cutting Instead of Hardening the Hole

Drilling stainless steel is not simply a contest between the material and the hardest bit available. The decisive issue is whether the cutting edges continue removing metal. A sharp high-speed-steel drill can succeed in suitable stainless, while an expensive drill can fail quickly if it skates, rubs, overheats, or packs its flutes.

The practical objective is to clamp the work securely, match the tool to the stock and machine, choose a diameter-appropriate speed, lubricate the cut, and apply enough controlled feed to form chips. If the drill squeals, polishes the surface, or spins without advancing, stop. Continuing usually makes both the tool and the hole worse.

This guide synthesizes the supplied manufacturer, industrial, trade-publication, and community guidance; it does not report original comparative testing. Exact speed and feed settings should come from the drill manufacturer or a machining reference matched to the alloy, drill diameter, tool material, hole depth, coolant condition, and machine.

Why Stainless Steel Becomes Harder to Drill

Stainless steel may drill normally for the first few moments and then seem to become impenetrable. That change can be real. When a cutting edge rubs or burnishes the metal instead of shearing off a chip, it plastically deforms the surface. This deformation can increase surface hardness and strength—a process known as work hardening.

Common austenitic grades such as 304 and 316 are particularly susceptible when machined improperly. A cutting-tool manufacturer’s guide to drilling stainless steel identifies excessive RPM combined with insufficient feed as a cause of rubbing, retained heat, and localized hardening in these grades.

A typical failure cycle looks like this:

1. The drill starts with too little feed, unsuitable speed, a dull edge, or inadequate rigidity.
2. Instead of biting into fresh material, the cutting lips slide across it.
3. Rubbing produces plastic deformation and frictional heat.
4. The affected layer becomes harder to cut.
5. The drill meets greater resistance and rubs even more.
6. The cutting edges wear, the hole becomes polished, and progress stops.

Heat matters, but it is not the complete explanation. Work hardening is fundamentally associated with deformation.

Stainless steel’s relatively low thermal conductivity compounds the problem. Cutting heat tends to remain near the drill tip rather than spreading rapidly through the workpiece. The cutting lips therefore operate in a demanding local environment even when the rest of the part remains comparatively cool.

Chip behavior adds another difficulty. Stainless is ductile, so chips may be long and reluctant to break. They can wrap around the drill, pack into the flutes, obstruct cutting-fluid delivery, and increase friction. Loaded flutes can contribute to vibration, poor hole finish, cutting-edge damage, or tool failure.

The governing test throughout the job is not simply whether the motor is turning. Ask instead:

• Is the drill visibly advancing?
• Are both cutting lips producing chips?
• Does the sound suggest cutting rather than squealing?
• Is the hole developing as a cut surface rather than a bright, polished dimple?
• Are the flutes carrying chips out rather than becoming packed?

A drill that is cutting can be managed. A drill hovering at the surface or polishing the bottom of the hole needs to be stopped and reassessed.

Choose the Bit for the Hole and the Rigidity of the Setup

There is no single “stainless steel bit” that is best for every hole. Tool choice depends on the stainless grade and condition, hole diameter and depth, number of holes, stock form, and—critically—the rigidity and alignment of the machine.

Sharp HSS: viable under suitable conditions

A sharp high-speed-steel twist drill can drill common annealed stainless when speed, feed, lubrication, alignment, and chip evacuation are appropriate. HSS is comparatively tough and forgiving, which can be useful with a handheld drill or light drill press where minor vibration and deflection are difficult to eliminate.

That does not mean any HSS drill will work. A dull general-purpose bit starts by rubbing. Poorly ground or damaged cutting lips may load unevenly, enlarge the hole, or make the drill wander. HSS is also not ideal for every stainless grade, hardened area, deep hole, or repetitive production job.

The practical attraction of HSS is not that it compensates for bad technique. It is that a sharp HSS drill can be economical and less prone to brittle edge failure in an imperfect setup.

Cobalt HSS: a practical upgrade

Cobalt drills are still high-speed steel, but cobalt is alloyed into the tool material to improve heat and wear resistance. M35 commonly contains about 5% cobalt, while M42 commonly contains about 8%. Cobalt percentage alone does not determine performance; geometry, manufacturing quality, edge preparation, rigidity, coating, and correct operation also matter, as Kennametal explains in its comparison of cobalt and carbide drills.

Because cobalt is distributed through the drill rather than applied solely to its surface, the substrate retains its characteristics after correct resharpening. Cobalt HSS is therefore a practical upgrade for repeated holes, tougher conditions, or work in which ordinary HSS has worn prematurely.

Cobalt has a tradeoff: it is generally less forgiving than ordinary HSS of bending and side loading. Use it as a cutting tool, not a lever. With a handheld drill, brace yourself and keep the tool aligned instead of rocking the bit around the hole.

Solid carbide: productive, but dependent on rigidity

Solid-carbide drills can offer high wear resistance and productivity. On a rigid production machine with low runout, accurate alignment, secure fixturing, and suitable coolant delivery, carbide may be an excellent choice.

It is not automatically an upgrade for a handheld drill. Carbide is much less tolerant of vibration, deflection, interrupted engagement, side loading, and spindle misalignment. Under those conditions, an edge can chip or the drill can break suddenly. A light drill press should not be assumed sufficiently rigid merely because the tool is mounted vertically.

Choose carbide because the machine and process can support it—not because previous drills have already failed. If the setup caused HSS or cobalt to rub, installing a more brittle carbide drill without correcting that setup may simply create a more expensive failure.

Point geometry and coatings

A 135-degree split point is worth considering for stainless. It can reduce walking and help the cutting lips engage sooner, particularly on a smooth surface. It does not guarantee a successful hole; the drill must still be sharp, aligned, and fed correctly. Regal’s stainless-drilling guidance also describes split-point geometry, short tool overhang, and chip evacuation as parts of the overall process.

Do not confuse tool substrate with coating:

• HSS, cobalt HSS, and solid carbide describe the primary tool material.
• TiN, TiAlN, and similar labels describe coatings.
• A gold or titanium-colored drill is not made from solid titanium.
• Sharpening a coated drill may remove coating from the cutting edge, although the underlying drill can remain usable if ground correctly.

Match the tool form to the hole

A suitable step bit can be useful for graduated larger holes in thin sheet.

Large diameters may call for a suitable hole saw, annular-style tool, punch, or another hole-making process. These tools are not interchangeable. Each has distinct requirements for machine torque, pilot control, material thickness, clearance, lubrication, and workholding.

For a general overview of twist drills, step bits, and hole saws, see Drill Review’s guide to common drill-bit types. That guide provides tool-category context rather than stainless-specific performance evidence; the substrate, geometry, and operating parameters still have to suit the actual job.

Prepare the Workpiece and Control the Main Hazards

Preparation is part of the cutting process. A well-selected drill can still fail if the work moves, the tool starts off-center, or the operator loses alignment at breakthrough.

Wear eye protection and secure the work

Wear safety glasses before starting because a drill can break under heat and load and project fragments. Clamp the workpiece firmly rather than trying to restrain it by hand; if the bit catches at breakthrough, an unsecured plate, bracket, or tube can rotate with serious force. These hazards are addressed directly in SAIL’s stainless-steel drilling safety guidance.

A small part resting flat on a drill-press table can still spin if it is not secured.

Control alignment and overhang

Keep the drill axis aligned with the intended hole. Misalignment places unequal loads on the cutting lips and introduces side force. This is especially damaging to cobalt and carbide tools, but it can also bend or break small HSS drills.

Use the shortest practical length of drill protruding from the chuck. Excessive overhang increases leverage and deflection. Check that the shank is held securely and that the bit runs reasonably true before bringing it into the material.

With a handheld drill, position your body so you can resist torque without leaning the drill sideways. With a drill press, confirm that the table and workholding remain stable under feed pressure.

Mark the location

A smooth stainless surface gives the point little guidance. Mark the hole accurately and make an appropriate center mark where the component permits it. The mark should locate the drill without creating an unnecessarily deformed crater.

A sharp split-point drill may need less help than a conventional point, but it still benefits from accurate positioning. If the drill repeatedly skates away from the mark, stop and improve location control rather than pressing harder at an angle.

Treat pilot holes as conditional

A pilot hole can improve stability and accuracy in some deep holes or help establish the path for a larger tool. It is not mandatory for every stainless-steel hole.

Use a pilot when it solves a defined problem—such as location, depth, stability, or the needs of a particular large-diameter tool.

There is no evidence-supported universal pilot size or progression for all stainless drilling. Choose the pilot arrangement from the final tool manufacturer’s guidance and account for whether the work is sheet, tubing, plate, or solid stock.

Inspect the drill and plan for breakthrough

Examine both cutting lips before starting. Reject or correctly resharpen a drill with chipped corners, rounded edges, obvious asymmetry, or damaged flutes. A dull bit encourages rubbing from first contact.

Breakthrough deserves advance planning because cutting resistance changes abruptly as the remaining material thins. Do not release the clamps until the spindle and tool have stopped fully; SAIL’s guidance specifically warns about bit breakage and workpiece rotation at breakthrough.

Sharp, stringy stainless chips are also a recurring caution in this metal-fabrication discussion.

Set Speed and Feed Without Relying on a Universal RPM

No single RPM is correct for every stainless-steel hole. “Run it slowly” is directionally useful, but too vague to be a complete setting.

A suitable starting point depends on:

• Stainless grade and condition
• Drill diameter
• Drill substrate and coating
• Point geometry and edge preparation
• Hole depth and whether it is blind or through
• Cutting fluid or coolant delivery
• Machine power and torque
• Chuck and spindle runout
• Tool overhang
• Workholding and overall rigidity

The drill manufacturer’s data should be the first reference. Match the recommendation as closely as possible to the workpiece grade, tool diameter, substrate, coating, hole depth, and coolant condition. A machining reference with stated assumptions is preferable to an isolated RPM copied from a forum.

Why diameter changes RPM

The cutting lips travel fastest at their outer edges. As drill diameter increases, the outer corner covers more distance during each revolution. Larger drills therefore generally require lower RPM to maintain a comparable cutting-edge surface speed.

This is why a bare instruction such as “use this RPM” is incomplete. The same setting could be excessive for one diameter and unnecessarily slow for another. It also says nothing about stainless grade, drill material, coolant, or rigidity.

Controlled speed does not mean the lowest setting at any cost

Stainless is commonly drilled at controlled rather than excessive rotational speed because high cutting speed can concentrate heat and accelerate wear. Yet the lowest available RPM does not guarantee success. If feed is too light, the drill can still rub at low speed.

An industrial materials guide notes that both excessive speed and speed that permits rubbing can cause trouble, illustrating why speed and feed must be considered together.

When a handheld drill or basic press cannot match the recommended RPM exactly, select the nearest practical controlled setting that the machine can maintain under load. Do not compensate for a speed mismatch by letting the drill hover, forcing a stalled motor, or allowing the tool to spin without advancing. If the machine cannot sustain a chip-forming cut, change the tool, hole-making strategy, or machine.

The operational definition of appropriate feed is more useful than an instruction to “push hard”:

Apply enough steady axial force to keep the cutting lips engaged, produce chips, and advance the hole without stalling, deflecting, or breaking the tool.

That force cannot be universal. A small drill may bend or snap under pressure that a larger drill tolerates. Thin sheet can distort. A low-powered handheld drill may stall before the tool reaches an effective cutting condition. Near breakthrough, the same feed that worked through the main thickness can cause grabbing.

Use the cut as feedback

Once tool-specific starting parameters are set, watch and listen:

• Visible, controlled advancement indicates material removal.
• Chips emerging from both flutes suggest both cutting lips are engaged.
• A polished dimple with little swarf suggests rubbing.
• Intermittent squealing may indicate loss of engagement, dullness, or vibration.
• A slowing motor may indicate excessive force, chip packing, insufficient torque, or an overly aggressive setting.

These observations help refine the process, but they do not replace manufacturer parameters. Chip appearance alone cannot reveal the exact surface speed or feed rate.

A Step-by-Step Method for Making the Hole

The following sequence is a conditional method, not a fixed recipe. Adapt the tool, speed, feed, and chip-clearing cycle to the stock and machine.

1. Choose and inspect the drill. Match the tool form and substrate to the hole and setup. Confirm that the cutting edges are sharp, balanced, and undamaged.

2. Secure the work and protect your eyes. Clamp the stock against rotation, lifting, and feed force, and wear safety glasses because the bit can break or catch under load. Industrial guidance likewise calls for eye protection and firm clamping when drilling stainless steel.

3. Clear the work area. Remove the chuck key and loose tools. Arrange the clamps and backing support so they do not interfere with the drill’s path.

4. Locate the hole and align the drill. Use an accurate mark, suitable center mark, or split point as the job requires. Minimize drill overhang and verify that the axis matches the intended hole direction.

5. Set the starting speed. Use drill-manufacturer or machining-reference data matched to the tool and material. If the machine offers only fixed steps, use the nearest controllable setting that can maintain the cut under load.

6. Apply suitable cutting fluid. Use a cutting fluid intended for the operation and apply it at the hole before or as cutting begins. Its role is to reduce friction and help control heat; it cannot compensate for a dull drill, inadequate feed, severe misalignment, or unsuitable speed.

7. Establish the cut. Bring the rotating drill into controlled contact. Feed firmly enough for the lips to bite and generate chips. The center mark should become a cut, not a mirror-bright polished depression.

8. Maintain steady advancement. Keep the drill aligned and avoid lateral leverage. Do not pause with the cutting edges spinning against the bottom of the hole. If the drill stops advancing, stop the spindle and diagnose the cause.

9. Clear chips when necessary. In a deeper hole, withdraw decisively when chips accumulate or the flutes begin loading. Stop the spindle fully and wait for the tool to become motionless before a brush, pliers, hook, or any other chip-removal tool approaches the swarf. Clear the flutes, reapply cutting fluid, and resume with enough feed to cut immediately; never handle sharp stainless swarf with bare fingers, as cautioned in this shop discussion of stainless drilling.

10. Control breakthrough. As resistance begins to fall, reduce axial force while maintaining alignment. Keep the work clamped until the spindle and drill have stopped completely.

11. Inspect before repeating. Clear chips safely, inspect the hole, and check the cutting corners. Correct any deterioration in edge condition or hole quality before drilling the next location.

Purposeful pecking is not the same as repeatedly tapping the surface. A useful cycle withdraws the drill far enough to evacuate loaded chips and deliver fresh fluid. Rapid, shallow pecks can repeatedly rub the same area without accomplishing either task. Each re-entry should resume a controlled, chip-forming cut.

This method does not endorse motor oil, penetrating spray, cooking oil, or other improvised substitutes. The supplied evidence does not establish their compatibility, fumes, fire behavior, staining, hygiene, or cleanup implications across different jobs.

Adjust the Method for Sheet, Plate, Deep Holes, and Different Machines

The same pressure, pilot sequence, and tool choice should not be applied to every form of stainless.

Thin sheet

Clamp it securely and support it close to the hole. A suitable step bit can be useful for graduated larger holes.

Feed must remain sufficient to cut, but moderate it as each step approaches breakthrough. If the finished face matters, test the method on scrap of the same grade and thickness first. A punch or suitable hole saw may be preferable for some diameters if the stock and equipment meet that tool’s requirements.

Thick plate and solid stock

For plate or solid stock, use a sharp twist drill of appropriate length and diameter. Sustained chip-forming feed matters because the cutting edges remain engaged longer than in sheet. Lubrication and deliberate flute clearing become increasingly important as hole depth grows.

Avoid unnecessary tool overhang. If a long drill is being used only because it happens to be available, a shorter drill may provide a more stable cut.

Deep holes

Plan the chip-clearing cycle rather than waiting until the flutes are completely packed. Stop the spindle before clearing the drill, replenish fluid, and re-enter without hovering at the bottom. A pilot hole may improve stability and accuracy in some deep-hole applications, but its size and necessity depend on the final tool and process. There is no universal peck depth or interval.

Tubing and curved stock

Tubing can rotate, crush, or allow the drill to skate off its curved surface. Use workholding that resists rolling and distributes clamping force appropriately. Confirm the location and drilling angle before starting.

Decide in advance whether the job calls for drilling one wall or passing through both, and support the stock and tool accordingly.

Handheld drills

With a handheld drill, HSS or cobalt HSS is generally more forgiving than solid carbide. Brace securely, keep the bit short, and avoid side loading. Choose a drill with adequate low-speed control and torque for the diameter, while recognizing the machine’s limits.

If the drill cannot maintain controlled rotation while producing chips, more body weight is not necessarily the answer. Reconsider the diameter, tool, pilot strategy, or machine.

Drill presses

Nevertheless, presses vary greatly in spindle runout, quill play, belt condition, table rigidity, chuck quality, and low-speed torque.

Do not infer that every drill press is automatically suitable for solid carbide. Harvey Performance’s tool-substrate guidance emphasizes carbide’s vulnerability to vibration, shock, and non-rigid conditions.

Rigid production machines

A rigid machining center can take advantage of carbide tooling, controlled feed, accurate speed, and enhanced coolant delivery. In that environment, greater productivity may justify the tooling and setup cost.

Exact parameters must still come from the drill manufacturer. Production drills may have geometry, coatings, through-tool coolant, and feed requirements that bear little resemblance to those of a general-purpose drill used in a maintenance shop.

Read the Cut: Symptoms, Causes, and Corrections

The cut often provides warnings before complete failure. Use this matrix to decide when to continue, adjust, or stop.

Symptom	Likely causes	Corrective action
Drill skates or wanders	Poor location control, dull point, unsuitable geometry, excessive overhang, or misalignment	Stop. Check the center mark, point condition, split-point geometry, overhang, and drill axis.
Squealing with little advancement	Rubbing, dullness, feed that is too light, or vibration	Stop rather than polish the surface. Inspect the edge and reassess speed, feed, alignment, and rigidity.
Bright polished dimple but no chips	Burnishing instead of cutting	Stop the spindle, remove the drill, inspect it, and correct the setup before the affected area worsens.
Progress begins and then stalls	Work hardening, edge wear, chip packing, loss of lubrication, or inadequate machine torque	Stop and inspect the drill and hole. Clear the flutes, restore fluid, and review speed and feed.
Chips pack into the flutes	Inadequate clearing cycle, ductile chips that are not breaking, or poor fluid access	Stop the spindle fully, clear chips with a suitable tool, reapply fluid, and use more deliberate clearing cycles.
Drill bends or repeatedly breaks	Excessive force, side load, overhang, runout, poor clamping, or an unsuitable tool	Shorten the setup, correct alignment and workholding, moderate force, and reconsider the drill substrate.
Carbide edge chips	Vibration, interrupted engagement, deflection, runout, or inadequate rigidity	Do not keep replacing carbide. Correct the machine and fixture or change to a tougher substrate.
Tool grabs at breakthrough	Excessive feed, weak clamping, unsupported thin stock, or loss of alignment	Improve support and workholding, maintain alignment, and reduce force as the point exits.
Long, continuous chips	Material is being removed, but ductile chips are not breaking	Keep clear while the spindle turns. Stop fully before removing chips with a suitable tool.
Hole becomes rough or oversize	Unequal cutting lips, runout, deflection, chipped edges, or chip recutting	Inspect the drill, chuck, alignment, and flutes before proceeding.

Chip color can provide a rough clue, but it is not a universal diagnostic. Some commercial tool guidance associates dark brown or black discoloration with excessive heat.

Chip shape also requires context. Long swarf may confirm that material is being removed, yet the same chips can wrap around the drill or workpiece.

The clearest stop condition is simpler: if the drill is no longer forming chips or visibly advancing, do not leave it spinning against the hole. Continued rubbing can glaze the surface, accelerate edge wear, and deepen the work-hardened layer.

Recover From a Work-Hardened Spot—or Choose Another Process

When a drill has stopped cutting, repeated attempts with the same dull tool and unchanged setup are rarely productive. Stop before the polished area expands or another drill is damaged.

Begin with the drill itself:

• Are the cutting corners rounded or chipped?
• Are both lips the same length and angle?
• Is material packed onto an edge?
• Are the flutes obstructed?
• Does the drill show evidence of overheating?
• Does it run true in the chuck?

Replace the drill or correctly resharpen a conventional drill where appropriate. Resharpening must restore balanced cutting lips and sufficient clearance; merely making the point look sharp is not enough.

Next, review the complete setup:

• Bit type, geometry, and sharpness
• Stainless grade and condition
• Diameter-appropriate speed
• Feed sufficient to form chips
• Cutting-fluid delivery
• Alignment and runout
• Workholding
• Tool overhang
• Machine torque and rigidity
• Chip evacuation
• Breakthrough support

Cobalt HSS may be a practical next tool if ordinary HSS wore rapidly under tougher conditions. It is not a guaranteed cure for a work-hardened surface. The replacement still has to penetrate the affected layer while remaining aligned and fed strongly enough to cut.

Solid carbide may be considered only when the machine, holder, workholding, and alignment are sufficiently rigid. It should not be treated as a handheld rescue bit. If the setup allows chatter or side loading, carbide may chip before penetrating the hardened area.

Do not treat annealing as a routine workshop correction. The supplied evidence does not establish a safe, material-specific annealing procedure for recovering a drilled component. Changing the hole-making method is generally the more controlled response when the available setup cannot restore a reliable cut.

Depending on stock thickness, geometry, diameter, finish requirements, and available equipment, options may include:

• A suitable step bit for thin sheet
• A properly specified hole saw
• A punch for compatible sheet or stock
• Controlled abrasive removal
• Plasma cutting
• Waterjet cutting

These are not interchangeable solutions. Each requires its own assessment of accuracy, edge quality, heat input, clamping, clearance, operator skill, and safety. Community machining advice presents punching, abrasive removal, plasma, and waterjet as possible alternatives when drilling is no longer practical, not as universally suitable remedies.

Change the process when the required diameter, stock geometry, hardened condition, available equipment, or breakage risk makes continued twist drilling uncontrolled.

Pre-Drilling Checklist

Before drilling stainless steel:

• Choose a sharp drill appropriate to the stock, hole, and machine.
• Wear eye protection and clamp the work against rotation, lifting, and breakthrough forces; industrial guidance emphasizes both precautions because drills can snap and unsecured work can move under load.
• Obtain tool-specific speed guidance rather than relying on one universal RPM.
• Apply suitable cutting fluid.
• Keep the drill aligned with minimal overhang.
• Feed steadily enough to form chips.
• Moderate force for small drills, thin sheet, low-powered machines, and breakthrough.
• Stop the spindle fully before clearing chips or releasing the work.
• Stop drilling if the tool squeals, polishes the surface, or ceases to advance.

Low speed by itself is not the solution. The decisive distinction is cutting versus rubbing. If the drill stops producing chips, inspect the tool and setup before the hardened spot becomes worse, and change tooling or processes when the available equipment cannot complete the cut under control.

Frequently Asked Questions

Can a standard HSS drill bit drill stainless steel?

Yes. A sharp HSS twist drill can drill common annealed stainless when it is correctly aligned and the speed, feed, lubrication, and chip evacuation are suitable. HSS is not automatically inadequate simply because the workpiece is stainless.

Its limits become more apparent in tougher grades, repetitive work, deep holes, partially hardened surfaces, and conditions that create substantial heat or wear. If the drill is already dull, changing only the RPM will not restore its ability to cut. Cobalt HSS may be a useful upgrade, but technique remains essential.

Is cobalt better than carbide for a handheld drill or drill press?

For a handheld drill, cobalt HSS is generally the more practical and forgiving choice. It offers better heat and wear resistance than ordinary HSS while tolerating imperfect conditions better than solid carbide. It must still be kept aligned because bending and side loading can damage it.

For a drill press, the answer depends on the machine. Cobalt remains suitable for light presses, repairs, prototypes, and low-volume work. Solid carbide may outperform it only if the press or machine has low runout, accurate alignment, rigid workholding, and enough stability to prevent chatter and deflection. A drill press is not automatically rigid enough for carbide.

Should I drill a pilot hole in stainless steel?

Only when the pilot solves a specific problem. It can improve location, stability, and accuracy in some deep holes and may help prepare for certain larger tools. It is not universally required.

Avoid applying one pilot diameter or progressive sequence to every job. Additional enlargement stages create more opportunities for rubbing. Follow the final tool manufacturer’s guidance and account for whether the work is sheet, tubing, plate, or solid stock.

What should I do if the stainless steel has already work-hardened?

Stop drilling and inspect the cutting edges. Replace or correctly resharpen a dull conventional drill, clear the flutes, and reassess speed, feed, lubrication, alignment, overhang, workholding, torque, and machine rigidity before restarting.

A cobalt drill may help where ordinary HSS has worn, but it is not certain to penetrate a severely hardened layer. Carbide is a possible option only in a rigid, accurately aligned setup. If the available machine cannot keep the tool cutting under control, switch to a suitable hole saw, punch, abrasive method, or another appropriate hole-making process rather than repeatedly glazing the same spot.

Why is my drill bit spinning but producing no chips?

The cutting lips are probably rubbing instead of shearing material. Likely causes include a dull or damaged drill, insufficient feed, unsuitable speed, work hardening, poor alignment, excessive runout, inadequate rigidity, or packed flutes.

Stop the spindle rather than waiting for the drill to bite eventually. Inspect the tool and hole, clear the flutes after the tool has stopped, restore cutting fluid, and correct the setup. Resume only when the drill can engage with a controlled, chip-forming feed; otherwise, change the tooling or process.